Solution
To solve (2+1)4, we can use the binomial theorem, which states that:
(a+b)n=∑k=0n(kn)an−kbk
Here, a=2, b=1, and n=4. Applying the binomial theorem, we have:
(2+1)4=∑k=04(k4)(2)4−k(1)k
This simplifies to:
(2+1)4=(04)(2)4(1)0+(14)(2)3(1)1+(24)(2)2(1)2+(34)(2)1(1)3+(44)(2)0(1)4
Calculating each term separately:
- (04)(2)4(1)0=1⋅4⋅1=4
- (14)(2)3(1)1=4⋅22⋅1=82
- (24)(2)2(1)2=6⋅2⋅1=12
- (34)(2)1(1)3=4⋅2⋅1=42
- (44)(2)0(1)4=1⋅1⋅1=1
Summing these results:
4+82+12+42+1=17+122
So,
(2+1)4=17+122
Would you like further details or have any questions?
Here are some related questions for further practice:
- What is the expansion of (2−1)4?
- How do you simplify (3+1)3?
- What is the value of (2+3)2?
- How do you use the binomial theorem to expand (x+y)5?
- What are the coefficients in the expansion of (x−1)4?
- How do you find the middle term in the expansion of (a+b)6?
- What is the expansion of (5+2)3?
- How do you simplify (3−1)3?
Tip: When working with the binomial theorem, it's often helpful to write out a few terms to identify patterns before calculating the entire expansion.